1. Field of the Invention
The present invention relates generally to the determination of fluid chemistries by photometric analysis. More particularly, the present invention provides a simple, compact, and reliable photometric system in which a fluid sample, which is typically blood or another body fluid, e.g., urine, saliva, serum, or plasma, is automatically separated and analyzed to simultaneously measure the concentration of a number of fluid components.
2. Description of the Background Art
Methods for the photometric determination of fluid chemistry are known in the art. According to such methods, a sample is drawn from the patient and then, in the case of blood, typically centrifuged to separate the blood plasma from the blood's cellular components. After centrifugation, quantities of the separated fluid are mixed with one or more reagents. The various fluid-reagent mixes are then placed into sample cuvettes and light of predetermined wavelengths is passed through the cuvettes. This light is partially absorbed by the products of the reactions between the reagents and components of the fluid. The degree to which the light is absorbed is dependant upon the concentration of the reaction product in the fluid sample.
By comparing the intensity of the light transmitted through the cuvette with a reference intensity, the concentration of a given product of the reaction between the fluid and the reagent can be determined. The concentration of the reaction product is then used to calculate the concentration of a corresponding component in the sample fluid.
Apparatus for performing photometric analysis of fluids including blood samples is known in the art. However, known systems are in general cumbersome and expensive. Moreover, use of these known systems is labor intensive, time-consuming, and generally requires highly skilled laboratory personnel.
It would therefore be desirable to provide a compact, relatively inexpensive, and highly automated system for the rapid centrifugation, analysis, and measurement of components present in fluids including blood or other body fluid samples. It would be desirable if such a system were sufficiently inexpensive to be purchased by hospitals and small clinics so that fluid analysis could be performed on site rather than at a special laboratory located elsewhere. It would further be desirable if such a system were sufficiently automated so that it could be used reliably and with great precision even by a person with little or no specialized training.